The present invention relates to the operation of a thermal control system on a combustion turbine, and more particularly to an anti-icing system that uses a heat source located external to the combustion turbine.
Operators of combustion turbines, including aero-derivatives, seek the maximum output and efficiency from the machines. This typically occurs when operating at baseload. During baseload operation the majority of compressed air from the compressor section is combusted; and the inlet guide vanes (IGVs) are full opened, allowing the compressor to drawn in the maximum amount of air from the ambient environment.
To generate additional power from an existing combustion turbine, an inlet air conditioning system is commonly used. The air conditioning system increases the airstream density by lowering the temperature of the airstream entering the compressor section of the combustion turbine. This increases the mass flowrate of the airstream entering the compressor, resulting in increased efficiency and power output of the combustion turbine. An air conditioning system may have the form of, for example, but not limiting of, a chiller system located within an inlet system of the combustion turbine.
However, baseload operation or maximum output from the combustion turbine, though desired by operators, is not always feasible. There may not be a demand in the energy market (electrical grid, or the like) for all of the energy generated at baseload. Here, the combustion turbine must either be shutdown or operate at a partload, where less than the maximum amount of energy is generated. In some energy markets partload operation typically occurs during the evening or nighttime hours, when power demands generally subside.
Some combustion turbines operate in cold, humid ambient environments. These environments can allow ice to form within the inlet system and on components of the compressor section; which may be handful to the combustion turbine. Anti-icing systems are used to prevent or remove this icing. These systems may be a function of an inlet bleed heat system (IBH), which re-circulates hot compressor discharge air to the inlet system, raising the temperature of the inlet airstream. Furthermore, anti-icing systems typically modulate the IGVs to reduce the amount of air entering the compressor section. During anti-icing operation the power and efficiency of the combustion turbine are significantly reduced.
For the foregoing reasons, there is a need for an anti-icing system that does not significantly impact the output and efficiency of the combustion turbine. The system should incorporate an external heat source to increase the temperature of the airstream entering the compressor section. The system should integrate with a pre-existing air conditioning system to increase the airstream temperature.